Water-heater.



P. H. OEHLKE.

WATER HEATER.

APPLICATION FILED MAY 16. 1911.

1,017,012,. Patented Feb. 13, 1912.

2 SHEETS-SHEET 1 "ii 1 7 \t F. H. OEHL-KE.

WATER HEATER.

APPLICATION FILED MAY 16. 1911.

1,017,012, Patented Feb. 13,1912.

2 SHEETSSHEET 2.

COLUMBIA PLANOGRAPH CO.,WASIIINGTON. D. c.

FREDERICK H. OEI-ILKE, OF LORAIN, OHIO, ASSIG-NOR TO HOFFMAN HEATERCOMPANY,

OF LORAIN, OHIO, A CORPORATION OF OHIO.

WATER-HEATER.

To all whom it may concern:

Be it known that I, FREDERICK H. OEI-ILKE, a citizen of the UnitedStates, residing at Lorain, in the county of Lorain and State of Ohio,have invented a new and useful lVater-Heater, of which the following isa specification.

This invention has reference to improvements in water heaters, wherein aheating coil is housed in a jacket or casing, the water passing throughthe coil and the flame being directed against the exterior of the coilwithin the jacket.

The object of the present invention is to provide a heating coil of longlife and which may be readily cleaned, and where the products ofcombustion are brought into intimate contact through a tortuous pathwith the walls of the heating coil.

The invention comprises a casting usually of iron so constructed thatthe water traversing it must pass over the entire heating surface of thecoil, and the structure is such that the water is caused to traverse atortuous path through comparatively fiat conduits, and the products ofcombustion are also caused by the form of the coil to traverse atortuous path, whereby all surfaces of the branches of the tortuousconduit are subjected to the hot gases, thus greatly enhancing theefficiency of the structure. The coil is in the form of a singlecontinuous casting from end to end and of general serpentine shape withthe branches staggered so as to extend alternately to opposite sides ofa medial plane.

The invention will. be best understood from a consideration of thefollowing detailed description taken in connection with the accompanyingdrawings, forming a part of this specification with the understanding,however, that while the disclosure of the drawings is that of apractical form of the invention, the latter is susceptible of otherembodiments and, therefore, includes such changes and modifications asdo not mark a departure from the scope of the invention.

In the drawings :Figure 1 is an elevation of the heater with part of thecasing shown in longitudinal section. Fig. 2 is a top plan view of theheating coil with the casing omitted and drawn to a larger scale thanFig. 1. Fig. 8 is a section on the line 3-3 of Fig. 2. Fig. 4 is anelevation of the heating coil alone as viewed from the rightSpecification of Letters Patent.

Application filed May 16, 1911.

Patented Feb. 13, 1912.

Serial No. 627,587.

hand side of Figs. 1 or 2 and drawn to a larger scale. Fig. 5 is asection on the line 55 of Fig. 1, but drawn to the scale of the otherfigures.

Referring to the drawings, there is shown a casing 1, which so far asthe present invention is concerned, may be constructed in any suitablemanner. It is customary to form the casing of two steel jackets 2, 3with a lining 4 of some suitable refractory material, such as asbestosboard, there being a dead air space between the two jackets forthermo-insulation, whereby but little heat is lost through radiation.The jacket is provided with a cap or cover member 5 and a base member 6,through which latter fuel may be conveyed by way of a valve 7 and aircheck 8 to a burner, which because it does not enter into the presentinvention, has not been shown.

WVithin the casing there is housed a coil 9 constructed in accordancewith the present invention and provided at each end with tapped terminalmembers 10 and 11, respectively, whereby pipes 12 and 13, respectively,may be coupled to the coil for conveying water to and from the latter.The tapped terminal members 10 and 11 may be and usually are inalinement one with the other and in the longitudinal axis of the coil asa whole. The terminal member 10 communicates with a conduit branch 14,which in the main, is to one side of the longitudinal plane of thesection of Fig. 3, and this branch widens from the terminal membertoward the end remote from the terminal member, where it merges intoanother branch 15, which in the main, is to the other side of thelongitudinal plane of the section of Fig. 3 and inclines oppositely fromthe branch 14, the junction portion of the branch 14 with thecorresponding end of the branch 15 occupying about or a little more thanone half the width of the corresponding portion of the branch 15, andprojecting to a greater extent away from the medial plane underconsideration than the corresponding end of the branch 15.

That end of the branch 15 remote from the point of connection withbranch 14 is narrowed and the edge of the branch 15 remote from thebranch 14 is designated by the reference numeral 16 and is at, an angleto the plane of the section of Fig. 3.

In the particular showing of the drawings there are succeeding branches17 18, 19, 20

and 21 with a terminal branch 22 merged into the terminal axial member11, the branch 14 merging into the terminal axial member 10. V

The branches 18 and 20 have relatively straight edges 23, 24-,respectively, corresponding to the edge 16 of the branch 15, the edge 23approaching more nearly to parallelism with the plane of the section 'ofFig. 3 than does the edge 16, and the edge 24 passing the position ofparallelism and inclining in the opposite direction from the edge 23.The branches 17, 19 and 21 have relatively straight edges 25, 26 and 27,respectively, disposed similarly but oppositely to the edges 16, 23 and24L of the other branches, that is, the edges 25, 26 and 27 are on theopposite side of the plane of the section of Fig. 3 from the edges 16,23 and 21.

Each branch is comparatively wide at one end and narrows toward-theother end, and these branches are joined at alternately opposite endsone to the other in series with their junction portions all cut by theplane of the section of Fig. 3. The result of this construction is thatwhile there is provided a passage throughout the length of the coil 9,which passage is in general serpentine in form, but is directedalternately toward opposite sides of the medial plane coincident withthe plane of Fig. 3. Each branch at the end remote from the centrallongitudinal axis of the coil is rounded into conformity with thecylindrical shape of the inner wall of the casing, so that when housedin the casing these rounded edges indicated generally by the referencenumeral 28 may be placed into quite close proximity to the inner wall ofthe casing, so that the products of combustion must in a great measurefind passage through the casing other than between the edges 28 and theinner wall of the casing. This freer passage is provided by the spacesleft by staggering the sections of the coil with relation to the planeof the section of Fig. 3, so that the major portions of the sections arealternately on opposite sides of the plane under consideration, wherebythe products of combustion find free passage from the burner by one edgewall of the coil section nearest the burner, then by the edge of thenext section on the other side of the plane under consideration, andthen to the side of the next succeeding section on the same side of theplane under consideration as the first mentioned edge and so onthroughout the coil, the path of the freest passage of the products ofcombustion changing from one side to the other of the coil inalternation serially. The result of this is that the products ofcombustion will strike the wall of the coil nearest the burner and thenaround the edge of the section first engaged, over the upper face of thesame, considering the v coil as upright, and at the same time againstthe under face of the next higher coil section, thence across the upperface of the last named coil section and the under face of the stillhigher coil section and so on throughout the coil, whereby the productsof combustion follow a tortuous or serpentine path zigzagging throughthe coil from one side to the other until they finally escape throughthe top of the casing, which latter may be constructed in the usualmanner for such purpose.

lVater flowing through the coil, say entering through the pipe 13 andescaping through the pipe 12, first enters the section 22 where becauseof the flat and expanded form of the section, it is spread out into acomparatively broad sheet, thence to the section 21 where it is likewisespread out into a broad sheet, and so on through the several sectionsuntil it reaches the pipe 12. Assuming the water entering through thepipe 13 to be quite cold, it will be subjected to the heating effect ofthe flame direct against a comparatively broad surface presented by thesection 22, thence through the other sections to the outlet of the coilfor in each section the water is subjected to the heating effect of theflame or hot products of com bustion acting on a broad surface of metal,presenting to the water a broad heating surface much wider than thethickness of the column of water and the water is attacked by the heatover two broad surfaces separated by a comparatively thin layer ofwater, so that the temperature of the water is quickly raised because ofthe broad surface presented, while the products of combustion areconstrained to act on the heating surfaces for a comparatively longperiod of time due to the tortuous path through which the products ofcombustion will pass.

It will be observed that the water is directed through the coil in aserpentine path approching in form a flat helix described about thelongitudinal axis of the coil, the water being constrained to flow inwide thin channels of approximately segmental form in alternatelyinclined relation and extend ing on opposite sides of the centrallongitudinal axis of the coil but all cut by a central axial plane.Because of the disposition of the serpentine channels the path of theproducts of combustion also defines a serpentine path causing theproducts of combustion to move across the comparatively fiat faces ofthe segmental coil sections in a direction defined by a flat helixdescribed about the longitudinal axis of the coil.

In Fig. 5 the general cross sectional form of one of the sections, saythe section 21, is indicated and this may be taken as generally typicalof the cross sectional shape of all of the sections at correspondingpoints.

By the construction of the coil both the water and the products ofcombustion are constrained to approximately serpentine paths, eachapproaching in form a flat helix and the path of the water and the pathof the products of combustion are in interlaced relation, whereby theaction of the products of combustion upon the water is prolonged. Thisoccurs not only because of the comparatively long paths through whichpaths the water and the products of combustion must pass, but thebroadening of the water channels causes a comparatively sluggishmovement of the water through the coil, whereby it remains for acomparatively long time in operative relation to the heating medium, andso the heat units are very largely utilized.

Having thus fully described my invention, what I claim as new and desireto secure by Letters Patent, is

1. A serpentine water heating coil comprising successive laterallyextended sections joined together at alternate ends, the lateralextensions of successive sections being directed alternately towardopposite sides of the coil.

2. A serpentine water heating coil comprising alternate sectionslaterally extended in opposite directions with relation to thelongitudinal axis of the coil and joined together successively atalternate ends.

3. A serpentine water heating coil comprising a longitudinal series oflaterally extended sections joined together at alternate ends, theentire coilbeing comprised in a single casting, the sections having thelateral extensions on alternately opposite sides of the centrallongitudinal axis of the coil.

l. A water heating coil comprising a longitudinal series of relativelyflat laterally extended sections joined together at alternate ends andprovided with a continuous internal passage throughout of serpentine andapproximately fiat helical shape.

5. A water heating coil comprising integrally joined fiat approximatelysegmental sections connected alternately at the ends with a continuouspassage throughout the coil, the sections being staggered with relationto the longitudinal axis of the coil.

6. A water heating coil comprising a single casting provided with axialterminal members, and intermediate members joined at alternate ends atan angle one to the other and staggered with relation to thelongitudinal axis of the coil.

7. A water heating coil having a laterally extended water passagetherethrough of generally serpentine form and directed alternatelytoward opposite sides of a medial plane, said coil defining a path forthe products of combustion similar to the general shape of the waterpassage through the coil and in interlaced relation thereto.

8. A water heater comprising a heating coil having a serpentinelaterally extended water passage therethrough with alternate branches instaggered relation to the longitudinal axis of the coil, said coilhaving means at the ends for the attachment of water pipes thereto, aninclosing casing for the coil, and means for the application of heat tothe coil within the casing.

9. A water heater comprising a heating coil having a serpentinelaterally extended water passage therethrough with alternate branches instaggered relation to the longitudinal axis of the coil, said coilhaving means at the ends for the attachment of water pipes thereto, aninclosing casing for the coil, and means for the application of heat tothe coil within the casing, the coil having its members conforming inpart to Copies of this patent may be obtained for five cents each, byaddressing the Commissioner of Patents Washington, I). G.

